Want to go bust? Have a kid. Educate same. Why the middle class never had it so bad

In their pursuit of the good life, Michigan couple Mary and Tom Clark appear to be doing everything right. Both work--she as a middle-school teacher, he as an insurance claims adjuster--to support their two girls, ages 6 and 9. When the Clarks bought their four-bedroom house in Battle Creek six years ago, they put 20% down to get the best interest rate. They have no credit-card debt, economize every way they can--yet can't escape the feeling that they are just a pink slip away from financial disaster. "If Tom lost his job, we'd be hurting fast," says Mary. "I guess it...